Displaying Card Flip Animations

This lesson teaches you to

Try it out

This lesson shows you how to do a card flip
animation with custom fragment animations.
Card flips animate between views of content by showing an animation that emulates
a card flipping over.

Here's what a card flip looks like:

Card flip animation

If you want to jump ahead and see a full working example,
download and
run the sample app and select the Card Flip example. See the following
files for the code implementation:

src/CardFlipActivity.java

animator/card_flip_right_in.xml

animator/card_flip_right_out.xml

animator/card_flip_left_in.xml

animator/card_flip_left_out.xml

layout/fragment_card_back.xml

layout/fragment_card_front.xml

Create the Animators

Create the animations for the card flips. You'll need two animators for when the front
of the card animates out and to the left and in and from the left. You'll also need two
animators for when the back of the card animates in and from the right and out and to the
right.

Create the Views

Each side of the "card" is a separate layout that can contain any content you want,
such as two screens of text, two images, or any combination of views to flip between. You'll then
use the two layouts in the fragments that you'll later animate. The following layouts
create one side of a card that shows text:

Create the Fragment

Create fragment classes for the front and back of the card. These classes return the layouts
that you created previously in the onCreateView() method
of each fragment. You can then create instances of this fragment in the parent activity
where you want to show the card. The following example shows nested fragment classes inside
of the parent activity that uses them:

Animate the Card Flip

Now, you'll need to display the fragments inside of a parent activity.
To do this, first create the layout for your activity. The following example creates a
FrameLayout that you
can add fragments to at runtime:

In the activity code, set the content view to be the layout that you just created. It's also
good idea to show a default fragment when the activity is created, so the following example
activity shows you how to display the front of the card by default:

Now that you have the front of the card showing, you can show the back of the card
with the flip animation at an appropriate time. Create a method to show the other
side of the card that does the following things:

Sets the custom animations that you created earlier for the fragment transitions.

Replaces the currently displayed fragment with a new fragment and animates this event
with the custom animations that you created.

Adds the previously displayed fragment to the fragment back stack
so when the user presses the Back button, the card flips back over.

private void flipCard() {
if (mShowingBack) {
getFragmentManager().popBackStack();
return;
}
// Flip to the back.
mShowingBack = true;
// Create and commit a new fragment transaction that adds the fragment for
// the back of the card, uses custom animations, and is part of the fragment
// manager's back stack.
getFragmentManager()
.beginTransaction()
// Replace the default fragment animations with animator resources
// representing rotations when switching to the back of the card, as
// well as animator resources representing rotations when flipping
// back to the front (e.g. when the system Back button is pressed).
.setCustomAnimations(
R.animator.card_flip_right_in,
R.animator.card_flip_right_out,
R.animator.card_flip_left_in,
R.animator.card_flip_left_out)
// Replace any fragments currently in the container view with a
// fragment representing the next page (indicated by the
// just-incremented currentPage variable).
.replace(R.id.container, new CardBackFragment())
// Add this transaction to the back stack, allowing users to press
// Back to get to the front of the card.
.addToBackStack(null)
// Commit the transaction.
.commit();
}